UNIVERSITI PUTRA MALAYSIA

PROPERTIES OF POLYPHENOLOXIDASE OF SUGARCANE AND DEVELOPMENT OF METHODS TO PREVENT

DISCOLOURATION OF JUICE

MOHAMMAD SHAMSUL HOQUE

FSMB 1998 12

PROPERTIES OF POL YPHENOLOXIDASE OF SUGARCANE AND DEVELOPMENT OF METHODS TO PREVENT

DISCOLOURATION OF JUICE

By

MOHAMMAD SHAMSUL HOQUE

Thesis Submitted in Fulfilment of the Requirements for the Degree of Master of Science in the Faculty of Food Science and Biotechnology

Universiti Putra Malaysia

May 1998

DEDICATION

This piece of research work is dedicated as a token of respect and compliment to the happy soul of my deceased father Mohammed Mokbul Hossain.

'0 may Allah! Have mercy on him as he did care for me when I was very little/ forgive him and protect him from the torment of the grave and the torment of the hell fire and receive him with honour and admit him to the happy place 'Jannatul Ferdous' ......................... Ameen.

ACKNOWLEDGEMENTS

All praise is due to Almighty Allah Subhanahuwataala, who enables me to

complete this modest research. Peace and blessing of Allah be on His last prophet

Muhammad (SA W)

I feel proud in expressing my deep sense of gratitude and obligation to my

venerable advisor, Assoc. Prof. Dr. Salmah Yusof, Department of Food Technology,

Faculty of Food Science and Biotechnology, Universiti Putra Malaysia and Chairman

of the advisory committee for her inspiration, invaluable suggestions, constructive

criticisms, patience, unstinted co-operation and inexpressible guidance throughout the

progress of this research work and in the preparation of the manuscript.

I would express my sincere thanks to distinguished members of my advisory

committee Assoc. Prof. Dr. Hasanah Mohd. Ghazali, Deputy Dean of Faculty of Food

Science and Biotechnology and Assoc. Prof. Dr. Russly Abd. Rahman, Head of

Department of Food Technology for their worthy inspiration, constructive suggestion

and guidance to complete the work. My sincere thanks is due to Universiti Putra

Malaysia (UPM) for the fmancial support provided through the IRP A fund for this

research, which was awarded to Assoc. Prof. Dr. Salmah Yusof.

My special thanks to my reverend mother who is most dear to me for her

heavenly affection and great sacrifice for my education.

111

I specially acknowledge my boundless gratitude to my elder brother Dr.

Mohammad Abul Quasem and other members of my family for their constant

encouragement, which enabled me toward completing the study.

I would like to express my sincere thanks to Dr. Md. Salim Khan, Dr. Abdullah

Al-Ahsan , Mr. Zainal Samicho, Mr. Abul Hossain Mollah, Mr. Mohd. Soib Yusof, Puan

Naimah Ahmed, Mr. Mogen, Mr. Amri Ismail, Mr. Fadli Ghani and others for their co­

operation rendered during my research work in Malaysia.

I am thankful from the bottom of heart to staff of Faculty of Food Science and

Biotechnology for their understanding, co-operation, moral support and enthusiastic

acceptance as part of their community throughout my study here.

IV

TABLES OF CONTENTS

Page

ACKN"OWLEDGEMENTS ...................................................................... iii LIST OF TABLES ..................................................................................... ix LIST OF FIGURES ................................................................................... xi LIST OF PLATES ..................................................................................... xii ABSTRACT ............................................................................................... xiii ABSTRAK .................................................................................................. xv

CHAPTER ................................................................................................... 1

I. INTRODUCTION ................... ...... ..................................... ............. 1

II. LITERATURE REVIEW ............................................................... 3

Sugarcane .............................................. ................ ............................ 3 Origin of Sugarcane Cultivation ............................................... 3 Sugarcane Species and Varieties ................................................ 6 S ugarcane Varieties in Malaysia ................................................ 9 Botany of S. officinarum, var Yellow Cane ...... . .. .......... ..... . .. . . 14 Growth and Development ..... .................................................... 1 5

Gennination ....................................................................... 17 Tillering Phase ................................................. .................. 17 Cane yields ........... ................................................... .......... 18 Cane Ripening .............. . . . . . .. . ..... . . . . . . . . . . . . . . . . . . . . .............. ... .. . . 1 8

Sucrose Synthesis and Storage in the Plant ................... ............ 1 9

Biochemical Characteristics of Sugarcane ................... .................... 22 Composition of S ugarcane Juice .................................... ....... .... 22 Carbohydrate (Sugars and Non-sugars) ......... ........................... 23 Nitrogenous compound . . . ... . . . . . . . ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Mineral (Ash) .......................................................... ........ ..... ..... 26 Organic Acids ...................... ...................................................... 27 Titratable Acidity of Juice ......................................................... 27 pH .............................................................................................. 28 Dextran and Gums .......................................... .......................... 29

Harvesting and Storage of Sugarcane .......................................... . ... 29 Harvesting ............................................................ ..................... 29 Storage of Sugarcane ......... .......................................... .............. 30

v

Deterioration of Sugarcane ............... . ....................................... ........ 30 Enzymatic Deterioration .............................................. ............. 30 Chemical Deterioration ............... ................................. . ............ 31 Microbial Deterioration .......... .... ........ .......................... . ............ 31 Freeze Deterioration ......... . . ......... ............ . ................................. 31 Mechanical Deterioration ............ .............................................. 32 Pests and Disease ..... .......... ....... .. ................................. . ............ 32

Role of Enzyme in Sugarcane Juice .. . .............................................. 33

Inhibition of Polyp he no 1 Oxidase ...... ................................. . ............ 35

Chlorophyll ....... ........................... . ..... . ................................ ........... . . . 37

Viscosity ........................................................................................... 38

Role of Microorganisms in Sugarcane Juice ...................... . . ...... . ... .. 39

Blanching ......................................... . .. . ............................... . .. .......... 39

Sugarcane Juice Processing .............................................................. 40

m. EXTRACTION, PARTIAL PURIFICATION AND CHARACTERISATION OF POL YPHENOL OXIDASE FROM SUGARCANE (Saccharum officinarum var. yellow cane) 42

Introduction ..................................... . ... . ........ ......................... ........... 42

Materials and Methods ... ....... .............................................. .... . ........ 43 Materials .................. ................ . .. . .................................... ........ .. 43 Methods .............................. . .... .... ............................................. . 43

Preparation of Sample ....................................................... . 43 Extraction and Partial Purification of Polyphenoloxidase (PPO) .. ....................................... ... ...... 44 Determination of Enzyme Activity .......... .. ........................ 45 pH Profile ......... .......... . ......... .............................................. 45 Heat Stability .... . ........ ......................................................... 45 Inhibition ofPPO Activity ..................................... ............ 46 Protein Determination .......... .............................................. 46

Results and Discussion .................................................................. . . 46 Extraction and Partial Purification of PPO .. . ......... ... .. .. . ..... .... .46 Effect of pH on PPO Activity .. . ............................. ...... . . ... .. ..... .4 7 Thermal Heat Inactivation of PPO from Sugarcane ..... ............ .48 Variation of PPO Activity with Temperature ........................... 49 Effect of Inhibitors .................................................................... 50

vi

Conclusion ........................................................................................ 52

IV. EFFECT OF BLANCHING ON THE QUALITY OF SUGARCANE JUICE ................................................................... 53

Introduction ...................................................................................... 53

Materials and Methods ..................................................................... 54 Materials .................................................................................... 54 Methods ............ ................... ...................................................... 55

Blanching Treatments ........................................................ 5 5 Temperature Measurement during Blanching ................... 5 5 Physical and Chemical Analysis ........................................ 5 6 Detennination of Colour .................................................... 5 6 Detennination of Chlorophyll ............................................ 5 6 Extraction of the Active Crude Enzyme (PPO) ................. 57 Detennination of Tannin .................................................... 5 8 Sensory Evaluation ............. .............................................. 58 Statistical Analysis ................. ............................................ 59

Results and Discussion .................................................................... 59 Colour of Sugarcane Juice with Different Blanching

Treatment ............. .................................................................. 59 Chlorophyll ............. ........... ...................................................... 62 Heat Penetration Profile ............................................. ............... 64 Enzyme Activity ................. ........................ ............................... 65 Tannin of Cane Juice ................................................................. 66 Sensory Evaluation .................................................................... 67

Conclusion ......... ............................................................................... 72

V. PROCESSING AND STORAGE OF SUGARCANE JUICE .... 73

Introduction ...................................................................................... 73

Materials and Methods .................................. ................................... 74 Materials . . .................................................................................. 74 Methods .. . . ........................... ............ .......................................... 74

Preparation of Juice ............................................................ 74 Physico-chemical Analyses ............ .... ................................ 76 Detennination of Colour ........................................... ......... 76 Viscosity Detennination .................................................... 76 Microbiological Analysis ................................................... 77 Sensory Evaluation ............... ............................................. 77 Statistical Analysis ................ , . . . . . . . ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

vii

Results and Discussion .................................................................... 78 Total Soluble Solid ................................................................... 78 Titratable Acidity .................... .................................................. 79 pH .............................................................................................. 81 Sucrose ................................... . .................................................. 82 Reducing Sugars ........................................................................ 84 Colour ....................................................................................... 85 Viscosity .................................................................................... 88 Microbiology ............................................ 4 •••••••••••••••••••••••••••••••• 89 Sensory evaluation .................................................................... 90

Conclusion ................................... . . . .... ................. ............ ................ 94

VI. CONCLUSION AND RECOlVlMENDATIONS ............ .. . . ......... 95

BIBLIOGRAPHY ...................................................................................... 97

APPENDICES ................... .......................... ....................... .................. ..... 1 06

BIOGRAPIDCAL SKETCH ........................................................ ........... 1 33

viii

LIST OF TABLES

Table Page

1 . World Sugarcane Production for Sugar . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . 5

2. Total Land under Sugarcane Production (1967-1 979 ............................ 5

3. The present Position of Land Area under Sugarcane Cultivation in Malaysia ..................................... ..................................... 6

4. Main Commercial Sugarcane Vruieties in Malaysia ............................ 9

5 . Total Area of Yellow Canes Plantation in Peninsular Malaysia ........... 11

5. Area under Yellow Canes Cultivation's According to District and States .............................................................................................. 11

7. Composition of Sugarcane Juice and Juice Solids .................... ............ 22

8 . Carbohydrate Constituents of Sugarcane Parts ................ ..................... 24

9. Amides and Amino Acids in Raw Juice . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

10 . Mineral Constituents in Sugarcane Juice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

11. Organic Acid in Sugarcane Juice . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

12 . Extraction and Partial Purification ofPPO from sugarcane .... ............. .47

1 3. Effect of Inhibitors on PPO Activity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

14. Mean Values of Hunter "L", "a" and "b" of Sugarcane Juice Pressed from Blanched Cane Stalk and Stored at 5°C ........... .. . . ........... 60

1 5 . Mean Values of Total Chlorophyll of Sugarcane Juice Pressed from Blanched Cane Stalks and Stored at 5°C ........................ 63

16 . Panelists' Ranks for Colour of Sugarcane Juice after Water and Steam Blanching at different Times and Temperatures ............. ............................. ................................... . ........... 69

17 . Panelists' Ranks for Taste of Sugarcane Juice after Water and Steam Blanching at Different Time and Temperature . . . . . . .. . . . . . . . . . . . 70

18 . Panelists' Ranks for Colour and Taste of Cane Juice after Water and Steam Blanching at Different Time and Temperature ................ .................................... ................................... ... 71

1 9. Paired Comparison of Sensory Evaluation . . . . . .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

20 . Sensory Evaluation (overall acceptability) ............ . ............................... 93

IX

2 1 . Mean values of Tannin and Enzyme Activity loss (%) during Blanching of Cane Juice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 15

22. Mean Values of pH, TA and TSS of Sugarcane Juice during Storage . 1 1 6

23. Mean Values of Sucrose, Glucose and Fructose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 8

24. Mean values of Colour(Hunter L, a, b values) of cane juice

during Storage ...................................................................................... 1 20

25. Mean Values of the Microbial Count and Viscosity of Cane Juice Stored at different Temperatures and Treatments . . . . . . . . . . . . . . . . . . . . . . . 122

26. Critical Absolute Rank sum Differences for all Treatments Comparisons at 5% Level . . . . . . . . . . . .. . . . . . . .. . . .. . . . . . . ... .. . .... .. . . . .. . .. .. .. . . . . . .... . . . . 125

x

LIST OF FIGURES

Figure Page

1 . Effect of pH on PPO Activity ........................ ...................................... .4 7

2. Themlal Stability of PPO. The Enzyme was held at Various Temperature for 5 min . Prior to Cooling and Assay at 30°C ............... .48

3. Heat Inactivation of Pol yphenol oxidase at Various Times and Temperatures ......................................................................................... 49

4. Temperature Profile in the Cold spot of Heating and Cooling Sugarcane Stem ...................................................................... 64

5. Effect on Blanching on Enzymatic Activity Retention of Sugarcane Juice .......... ........................................................................... 65

6. Effect of Blanching on Tannin of Sugarcane Juice ............................... 66

7. Flow Chart for Processing and Preservation of Cane Juice .................. 75

8. Changes in TSS of Sugarcane Juice during Storage (with & without prEservative) ............................................................................ 78

9 . Changes in TA of cane Juice during Storage (with & without Preservative) ............ ....... ..... . . . ..... . .. .. . . . ........ . .... . .. . ........... ....... 80

1 0. Changes in pH of Sugarcane juice during storage (with & without preservative) ...... . .......... .............. ............... ............................... 8 1

1 1 . Changes in Sucrose of Sugarcane Juice during Storage (with & without Preservative) .......................... ..................... ................ 83

12. Changes in Glucose of Sugarcane Juice during Storage (with & without Preservative) ............................................................... 84

1 3. Changes in Froctose of Sugarcane Juice during Storage (with & without Preservative) ............................................................... 84

1 4. Changes in Hunter "L"values of Sugarcane Juice during Storage (with & without Preservative) ............................. ..................... 86

15. Changes in Hunter 'a' value of Sugarcane Juice during Storage (with & without Preservative) ................................ . . ................ 87

16. Changes in Hunter 'b' value of Sugarcane Juice during Storage (with & without Preservative) ................. ................................ 87

1 7. Changes in Viscosity (cP) of Sugarcane juice during Storage (with & without Preservative) ................... ............................... 88

Xl

LIST OF PLATES

Plate Page

1 . Sugarcane plant ................... ....... . ............................... .......................... 127

2 Sugarcane stem for blanching .............................................................. 127

3 . Blanching of sugarcane ........................................................................ 128

4 . Three roller crusher machine used for extraction of cane juice ........... 128

5 Deaereation ........................................................................................... 129

6. Fresh sugarcane juice . . ....... ................................................................. 129

7 Juice(with and without preservative) stored for 2 days

at 28°C, 5°C and - 1 8°C ........ .... . . ..... . . . ........... ....... .. .. .. . ......... ....... .......... 130

8 . Juice(with and without preservative) stored for 6 days

at 28°C, 5°C and - 1 8°C .. . . . ... ...... ..... . . ..... . . . ..... . ...... . . ...... . .... ... . .. . . ....... .... 130

9. Juice(with and without preservative) stored for 1 0 days

at 28°C, 5°C and - 1 8°C ......................................................................... 1 3 1

1 0. Juice(with and without preservative) stored for 12 days

at 28°C, 5°C and - 1 8°C .... . . ..... ... ........ ..... ..... . . . . ....... ...... . .. . ....... .......... . .. 1 3 1

1 1 . J uice( with and without preservative) stored for 1 6 days

at 28°C, 5°C and - 1 8°C . ........ .. . ..... . . ... ............... ......... .... ......... . . ...... ...... 1 32

xu

Abstract of the Thesis Presented to the Senate ofUniversiti Putra Malaysia in Fulfilment of the Requirements for the Degree of Master of Science.

PROPERTIES OF POL YPHENOLOXIDASE OF SUGARCANE AND DEVELOPMENT OF METHODS TO PREVENT

DISCOLOURATION OF JUICE

By

MOHAMMAD SHAMSUL HOQUE

May 1998

Chamnan : Assoc. Prof. Dr. Salmah Yusof Faculty : Food Science and Biotechnology.

The objective of the research was to develop a method to extend the shelflife of

freshly extracted sugarcane juice. The work focused on understanding the properties of

sugarcane juice as well as determining methods of preserving the colour.

Polyphenoloxidase (PPO) from sugarcane juice was extracted, partially purified and

characterised. Results indicated that the temperature for optimum PPO enzyme activity

was 30°C at pH 7.6. Heat inactivation studies showed that enzyme lost 50% activity by

exposure to 80, 75, 70 and 65°C for 1 .2, 2.8, 3 .6 and 7.8 min, respectively. The use of

ascorbic acid (O.SmM concentration), erythorbic acid (O.5mM concentration) and

sodium metabisulphite (O.5mM concentration) inhibited the browning reaction 80%,

74% and 92%, respectively.

The effect of different blanching conditions on the quality of juice was also

investigated. Sugacane was blanched at various temperatures and time intervals using

X111

both steam ( l 00 °C) and hot water (75°C, 80 °C and 85 °C). After blanching the juice

was analysed for chlorophyll content, colour, PPO activity and tannin content and

sensory evaluated for colour and taste. Unpeeled sugarcane stems which were steam

blanched for 13±1 min yield the highest quality juice.

A method to prepare an acceptable ready-to-drink bottled cane juice was

developed. The process consisted of steam blanching of unpeeled uncut cane followed

by the addition of 2S ppm. of ascorbic acid. Shelf life of cane juice with and without

preservative (ascorbic acid) packed in HDPE bottles stored at 28°C, SoC and -18°C

for up to 16 days were assessed in terms of physico-chemical characteristics,

microbiological quality, colour, viscosity and sensory properties. Results indicated that

samples stored at S and -18°C retained acceptable colour, flavour and taste for 1 0-12

days. The physico-chemical par�eters, such as pH, TSS, TA, sugars ( sucrose glucose

and fructose), L, a, b values, and viscosity varied little during 1 0-12 days storage at SoC

while they remained completely unchanged during 16 day-storage at -18°C.

xiv

Abstrak Tesis Yang Dikemukakan Kepada Senat Universiti Putra Malaysia Sebagai Memenuhi Keperluan Ijazah Master Sains.

CIRI-CIRI POLIPHONOLOKSIDASE TEBU DAN PENGEMBANGAN KAEDAH-KAEDAH PENGAWETAN TANPA PEWARNA JUS TEBU

Oleh

MOHAMMAD SHAMSUL HOQUE

Mei, 1998

Pengerusi : Prof. Madya Dr. Salmah Yusof Fakulti : Sains Makanan dan Bioteknologi

Objektifkajian ini adalah untuk menghasilkan kaedah penstabilan jus tebu bagi

penyimpanan jangkamasa panjang. Kajian yang terperinei telah dijalankan ke atas eiri-

eiri jus tebu dan kaedah pengawetan warna jus tebu. Enzirn poliphenoloksidase daripada

ekstrak jus tebu, telah ditulinkan dan dieiri. Keputusan yang didapati menunjukkan

aktiviti enzim adalah maksirnum pada suhu 30°C dan pada pH optimum 7.6. Kajian ke

atas penyahaktifan pemanasan pula menunjukkan bahawa enzirn dinyahaktifkan apabila

terdedah kepada suhu 80, 75, 70 dan 65°C selama 1 .2, 2.8, 3 .6 dan 7.8 minit masing-

masingnya, kehadiran asid askorbik, asid erythorbik dan sodium metabisulfite di dalam

jus tebu telah mereneatkan tindakbalas keperangan dengan begitu ketara sekali.

Di dalam kajian ini, kesan peneeluran pada keadaan yang berbeza-beza ke atas

kualiti jus tebu telah dilakukan. Perlakuan peneeluran dengan mengglmakan stirn

ataupun air panas (75, 80 dan 8SoC) telah dilakukan ke atas tebu. Selepas dieelur jus

tebu yang diekstrak dianalisa bagi klorofil, PPO, tannin, warna dan penilaian deria telah

xv

dilakukan ke atas jus tebu yang diekstrak daripada tebu yang dicelurkan. Perlakuan

penceluran selama 13 minit telah dilakukan ke atas tebu yang tidak dibuang kulitnya.

Adalah didapati hasilan jus tebu yang mengalami perlakuan penceluran mempunyai nilai

kualiti yang lebih tinggi daripada hasilan jus tebu tanpa mengalami perlakuan

penceluran.

Di dalam kajian ini, satu proses penyediaan jus tebu yang sedia diminum yang

telah dibotolkan di mana pedakuan penceluran tanpa pembuangan kulit diikuti dengan

penambahan agen perencat enzim telah diperkembangkan. Untuk menentukan hayat

penyimpanan jus tebu yang dicelurkan (13minit) dan dibotolkan di dalam botol HOPE

samada dengan penambahan bahan pengawet atau tanpa bahan pengawet dan disimpan

pada suhu 5 dan -1 SoC dan pada suhu bilik selama 16 hari, ujian seperti penentuan eiri­

eiri pisiko-kimia, kualiti mikrobiologi, wama, kelikatan dan penilaian deria telah

dilakukan. Adalah didapati sampel yang disimpan pada suhu 5 °c dan -1 SoC telah dapat

mengekalkan ciri-eiri penerimaan wama, rasa dan aroma selama 12 hari. Daripada

analisis yang dilakukan ke atas jus tebu yang disimpan pada suhu 5 °c dan -1 SoC selama

12 hari didapati tiada perubahan yang ketara pada nilai TSS, pH, TA, L, a, b, gula dan

kelikatan jus tebu. Sebaliknya jus tebu yang disimpan pada suhu bilik didapati tidak

dapat mengekalkan ciri wama, rasa dan aroma selepas penyimpanan selama 2 hari.

Daripada kajian ini, didapati bahawa tempoh hayat penyimpanan selama 12 hari adalah

sesuai bagi jus tebu yang disimpan pada suhu 5 dan -ISoC. Walau bagaimanapun,

didapati jus tebu yang disimpan pada suhu -1 SoC dapat mengekalkan kualiti

penyimpanan selama 16 hari.

xvi

CHAPTER I

INTRODUCTION

There are many varieties of sugarcane being cultivated in Malaysia, some are

grown for sugar production while others are for fresh juice consumption. Fresh

sugarcane juice is very popular as a refreshing drink throughout Malaysia because of

the tropical heat, high humidity and temperature.

Sugarcane juice has good organoleptic characteristics like flavour, colour and

taste. It has also calorific and medicinal values (Khamar et ai., 1 965). Sugarcane

juice has a great demand in Malaysia throughout the year for its thirst-quenching taste

and flavour; if these characteristics are retained in their original fonu, it can be a very

good bottled drink.

Proper methodology is yet to be developed to preserve the fresh cane juice.

After a certain period, the extracted juice undergoes marked deterioration in quality in

tenus of taste, colour and flavour, thus affecting its sensory characteristics. Previous

works have suggested that enzymatic browning was mainly responsible for

discolouration of sugarcane juice (Smith, 1978) and polyophenoloxidase, copper

containing catalyses the ortho- hydroxylation of monophenols and the oxidation of 0-

diphenols to o-quinones ( Mayer and Harel, 1979), is the major enzyme involved

1

2

A summary of the literature indicates that little work has been carried out in this

area. Khamar et al. (1965) initiated work in this area and reported that

conventional method of heat processing of the juice imparted a jaggery-like taste and

flavour. Rao et al. (1936) was of the opinion that changes in colour was due to both

enzyme action and metal contamination during juice extraction. According to Mann

and Singh (1988), the fresh sugarcane juice when blended with equal quantity of

whey/milk improve both the flavour and colour of the drink. They observed that the

shelf life of product was lengthened to one week at refrigeration (5-10oC) but beyond

this the quality deteriorated rapidly. The microbes proliferated very fast at ambient

temperature and fermented the sugars in juice within a few hours, making it sour and

unfit for human consumption (Sharma et al., 1989). Thus it is evident that preservation

of fresh juice with its keeping qualities intact is still a major problem. Considerable

research is needed to address the issue as to how it can be preserved for a longer time.

Therefore, the following objectives were set out for this study. These are: -

1. To understand the characteristics of the browning enzyme by extraction,

partial purification and characterisation of the enzyme polyphenoloxidise.

2 . To determine the effects of blanching on the quality of sugarcane juice

3. To evaluate the stability of sugarcane juice.

If these objectives are achieved, the problem of preservation of sugarcane juice

will be partially solved. Thus marketability will be easier and it will be a new economic

product in Malaysia

CHAPTER II

LITERATURE REVIEW

Sugarcane

Origin of Sugarcane Cultivation

Sugarcane has been grown since the earliest time. However, nobody knows for

certain where it was first cultivated. Researchers generally believe that sugarcane

originated either in Northern India (Sacchantm barbara, Jeswiet), Southeast China

(Sacchantm sinense, Roxb), or in the Malaya Archipelago (Rosenfeld, 1956).

According to Brandes (1956), New Guinea was the home of the Sacchantm

species where it is said to have been grown 8000 years ago as a garden plant, from

where it probably spread about 3000 years ago through the Malaya Archipelago, and

then to Indonesia and Bengal. Brandes (1956) described the migration of Sacchantm

officinantm that began approximately in the year 8000 BC from the Solomon Island to

the New Hebrides, and the New Hebrides to New Caledonia. The second migration

which began at about 6000 BC was by way of the Philippines, Borneo, Java, Malaya,

Burma to India; and the third, between the years AD 6000 and AD 1100 was from Fiji

4

to Tonga, Tahiti, the Marquees, Hawaii, as well as others part of Ocean. In Chinese

literature, sugarcane was cultivated in 475 BC in Southeast China. The Egyptians, who

were skilled in agriculture and chemistry (Deerr, 1950) developed clarification,

crystallisation and refining of sugarcane. Sugarcane later reached Morocco, South

Africa (AD 755), Sicily (AD 950), Madeira (1420) and the Canaries. Then it spread

in the 1500 from Santo Domingo to Mexico, Brazil, Peru and West Indian Island. In

1511, sugarcane was first planted in Cuba. Its cultivation was introduced in Mauritius,

Reunia, and Hawaii in the 1700 and Australia, Fiji and South Africa in the 1800. The

regions where sugarcane was produced before 1900's include Queensland, New South

Wales, Fiji, Hawaii, South and Central America, Mexico, Java, Egypt, Philippines,

South Africa, Mauritius, Caribbean's Island and India.

Since the beginning of the century, sugarcane has been successfully established

as an important agriculture crop for sugar production. Sugar is an indispensable

household commodity, which is widely used in food, beverage, drinks and many other

uses. World sugarcane production is given in Table 1

Malaysia started to grow sugarcane on a commercial scale during the 19th

century in Perak and Province Wellesley, mainly for sugar production (Tan, 1989).

However, the importation of sugar beet from Europe and rapidly developing oil palm

caused closure of many sugarcane plantations in 1913. Sugarcane industry was again

revived in the 1960's when the Government of Malaysia introduced its Agriculture

diversification program to overcome the country's dependence on imported sugar.

5

Table 1 : World Sugarcane Production for Sugar

Region and Country Area harvested Sugarcane Yield (1000 ha) (Kg/ha)

World 17606 61108 MalaysIa 23 67722 Bangladesh 181 39329 PakIstan 963 46144 IndonesIa 405 77778 AsIa 7873 58592 IndIa 3578 64561 ChIna 1058 52060 North Amenca 2755 55212 South Amenca 5222 68135 BrazIl 4213 66041 AustralIa 361 90582 Central Amenca 379 76251 ColumbIa 4213 90625 Thailand 945 39756 Phthppmes 380 73158

Source FAO (1994, StatlstIcal Year Book) Statistical Handbook, MalaYSia (1993)

Survey teams from Taiwan ( 1964) and Australia ( 1965) reported the feasibility of viable

sugarcane projects in northern part of Peninsular Malaysia (Tan, 1989) Tables 2 and

3 indicate the increasing sugarcane cultivation in Malaysia. Since 1967 to 1994, total

area under sugarcane cultivation has increased manifold from 6000 acres to 18000

hectares (Malaysia Statistical Handbook, 1993)

Table 2: Total Land under Sugarcane Production ( 1967-1979)

Name Location Approx. Area (ac.) Plantation start Johor PlantatIon & Indus Kula! 6000 1967 Perak Sugars Dmdmg 8000 1970 Perlls Sugars Chupmg 20000 1971 Negen Sembllan Sugars Bahau 10000 1972 Padang Terap Sugars Kedah 8000 1973 Source Tan, 1989

Table 3: The Present position of Land Area under Sugarcane Cultivation in

Malaysia

Year

1980 1986 1987 1988 1989 1990 1991 1992 1993 1994

Source: F AO (1994 Statistical Yearbook) Malaysia (1993, Statistical Handbook)

Sugarcane Species and Varieties

Hectare

12705 23318 20489 23970 23000 23000 23000 20000+ 18000+ 18000+

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Five species of sugarcane are cultivated in different parts of the world. These

are: -

l . Saccharum officinanlm

2. Saccharum robustum

'"' Saccharum barberi oJ.

4. Saccharum sinense

5. Sacchanlm spontaneum

Each of the species can be sub-divided into varieties with different genotype and

phenotypic characteristics. Sacchanlm officinarum known as 'Noble Cane' is rich in

sucrose and low in fibre content. The stems are vigorous and long and are used for

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commercial sugar production all over the world. Saccharum robustum, found in New

Guinea, is similar to the Noble Cane in its stem, leaf, and blossom characters. It is

higher in fibre and lower in sugar content than that in S. officinarum and hence suitable

for agricultural production. The stems are longer and vigorous. S. robustum when

crossed with S. ojficinarum, produces a popular hybrid which is fertile. S. barberi

called 'Indian Species' is sturdier than S. ojficinarum and is disease resistant. These

qualities, together with higher sugar and ample fibre content are used for breeding

purposes to enhance sugarcane production. S. barberi has few varieties namely

Sunnabile, Mango, Nargori and Saretha. Since they are less important their production

and chemical characteristic are not known (Jeswiet, 1927).

S. sinense, known as 'Chinese cane' has few varieties such as Dba, Oshima,

Cayania and Zwinga. The colour of the stem is green to greenbronze, and leaves are

long and narrow. The species is vigorous and resistant to infection. They have a low

sucrose, high fibre content unsuitable for manufacturing purposes. S. spontaneum

also known as 'wildcane', this variety is short and thin (less than 2-cm thickness), the

leaves are narrow and hard, and the plant is very sturdy and resistant to most diseases.

It is also known as 'wildcane'. S. officinarum has the following varieties: -

1. Otaheik - produced in Hawaii and Peru for many years

2. Cheribon - this comes from Indonesia (Java); the best known and widely

distributed is 'black cheribon'. In Latin America it is known as 'Morada'

or 'Regencia', in Louisiana purple; variation; light cheribon and striped

cheribon.

3. Preanger - this cane originated from Java; the noblest known in Latin

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America is Lacristalina ( Cuba) and has many synonyms.

4. Tanna-Caledonia -light, dark and striped Caledonia; the best known were

white and yellow Caledonia, Australia, Fiji, Mauritius, and Hawaii.

5. Beadle - this comes from New Guinea and from thence to Australia.

6. Black Borneo, Borneo

7. Creole - this is called 'Criolla' in Latin America and is identical with the

Indian pure variety.

None of these groups are cultivated commercially at present in the world,

although genetically they are resourceful. Old varieties deteriorate in their production

capacity and will have to be constantly replaced by more production, newer varieties of

sugarcane. According to Buzacott (1965), the reasons for deteriorative change in

sugarcane varieties include: -

1. Declining fertility of the sugar producing soil

2. The development of an unfavourable physical condition in soil

3 . The cumulative effect of disease and pest, and

4. The existence of symptom less or unidentified disease.

In recent years there have been few varieties developed in many parts of the

world. These hybrid varieties grow vigorously with increased yield from previously

20 - 35 tonelha which are resistant to diseases and pest infestation.

The promising and outstanding varieties of sugarcane grown all over the world

include the following: Co740, Co775, Co62174, Co8S1, Co8S3, Co9S1, Co957,